Problem: Rewrite ${((5^{-5})(3^{10}))^{-9}}$ in the form ${5^n \times 3^m}$.
Explanation: ${ ((5^{-5})(3^{10}))^{-9} = (5^{(-5)(-9)})(3^{(10)(-9)})} $ ${\hphantom{ ((5^{-5})(3^{10}))^{-9}} = 5^{45} \times 3^{-90}} $